- At 2018 solar makes economic, financial and environmental sense for both homeowners and business, looking to save electricity or generate electricity.
- There are two types of solar technology for end users
1. Solar thermal or solar water heating (SWH) which is designed to save the electricity (kWh’s) used in heating water
2. Solar electric or solar PV which is designed to generate electricity for immediate use, or to be stored in batteries
Solar Water Heating Technology
- There are many types of solar water heating system, all with the same aim of heating water using solar energy.
- Low pressure systems are generally used in low income homes, and high pressure where mains water and electric geysers are installed.
- There are several types of solar collector, evacuated tubes (EVT’s) filled with water, evacuated tubes (EVT’s) with heat piper risers, flat plate types both (direct and indirect), and integrated solar collectors with tanks. EVT’s account for approx. 85% of solar thermal collectors due to their lower cost and higher efficiency.
- There are also several design types: Integrated where the solar collector is part of the tank or split where the solar collector is separate to the tank.
- The heat transfer from solar to the water may be both direct and indirect. The process may be either thermos-syphon, (where the principle of heat rises) or forced circulation (pumped).
Types of Solar Water Heaters
Types of Solar Water Collector
Ubersolar Technology Advantage
- ‘Plug and play’, flexibility, simplicity, reliability, durability, high power, low maintenance and lower costs were all overriding priorities in the designs of the Ubersolar hot water heating systems.
- Overcoming the common problem of both underperformance and over performance were also priorities and was achieved by having vented solar collectors, limiting the maximum temperature in the solar collector to 99°C even when in stagnation (when no hot water is being used, for example when away on holiday).
- Consequently, the solar collector for both split systems and thermosiphon systems can be matched to absorb 100% of the solar irradiation necessary to replace 100% of the electricity used in heating any tank volume, also taking into account location, orientation and solar collector inclination.
- For retrofits where the existing electrical geyser is used, split indirect forced circulation systems are used in conjunction with a solar PV (electric) panel and solar pump. Temperature differential controllers are fitted to optimise efficiency on bigger systems.
- For new builds and for complete solar systems both split indirect forced circulation and close coupled thermosiphon systems can be used. The main difference is that close coupled systems require the storage solar tank to be put on the roof, while split systems enable the tank to be located inside, on walls or on the ground. Flat roof systems are available in both types. Pumped systems with the same size of collector as thermosiphon are typically 7%-12% more powerful.
- Evacuated tubes are used in preference to flat plate solar collectors because they produce more heat for less investment cost, and freezing conditions do not require the addition of glycol (vegetable antifreeze) which needs to be replaced periodically (every 18 months to 3 years) in flat plates in order to continue working. Evacuated tubes therefore avoid biannual maintenance charges.
- The end result is more power, more kWh savings, more hot water, more financial savings per Rand invested than any other solar water heating system, irrespective of type, when compared on a like for like basis.
- All solar water heating systems will save electricity and money.
- Ubersolar Water Heating Systems save more for less investment, require less maintenance, are more robust, do not suffer the common problem of overheating, will enjoy a longer life, combined with flexibility and all the advantages of ‘plug and play’.